| 摘要 |
PURPOSE:To detect accurately the deterioration of a developer and prevent beforehand the deterioration or the like of a development performance and an image quality, by operating a blackening rate from an exposure time that is according to a picture signal, and comparing it with a reference value. CONSTITUTION:A laser 31 is modulated by a modulation portion 30, and outputs a laser beam forming an image on a photosensitive drum. By the way, as for a signal, a radiation time is counted at a counter portion 32, and addition is made at a memory portion 501. Comparison with a reference value is made at a comparison portion 502, and when an addition value surpasses the reference value, a supply signal is outputted to a supply means 51. Also, the radiation time is outputted to a toner deterioration detecting means 52, and addition is made at a memory portion 521. And, at an operation portion 522, a blackening rate is calculated from the radiation time addition value and a transfer material size signal. And, a comparison portion 523 compares this blackening rate with a reference value and decides if it is a toner low consumption quantity or not. That is, if the blackening rate is small, toner consumption is small, and it follows that a stirring time has become long by staying in a development counter and deterioration has been realized. |
